CN117321307A

CN117321307A - Device for pumping a cryogenic fluid and filling station comprising such a device

Info

Publication number: CN117321307A
Application number: CN202280034329.2A
Authority: CN
Inventors: C·贝尼斯坦德-赫克托; M·格拉泽
Original assignee: LAir Liquide SA pour lEtude et lExploitation des Procedes Georges Claude
Current assignee: LAir Liquide SA pour lEtude et lExploitation des Procedes Georges Claude
Priority date: 2021-06-14
Filing date: 2022-05-05
Publication date: 2023-12-29
Also published as: CA3220390A1; KR20240021857A; FR3123951B1; WO2022263052A1; FR3123951A1; EP4355999A1

Abstract

Disclosed is a cryogenic fluid pumping device (1) comprising a sealed housing (13) intended to contain a pool of cryogenic fluid, the housing (13) containing a compression chamber (3) in communication with the pool and a movable piston (5) for compressing the fluid in the compression chamber (3), the piston (5) being mounted at a first end of a rod (50), the device (1) further comprising a drive mechanism (21) for driving a second end of the rod (50) to reciprocate in a longitudinal direction (A), the drive mechanism (21) comprising a motor (121) provided with a rotary shaft (211) and a mechanical conversion system (212) for converting the rotary motion of the shaft (211) into linear motion. In the operating configuration of the device (1), the longitudinal movement direction (a) of the rod (50) of the piston is vertical and the motor (21) is rigidly fixed to the upper frame (6, 26). The device (1) is characterized in that the mechanical transformation system (212) is also rigidly fixed to the upper frame (6, 16) comprising the frame (6, 26) of the motor (121) or a separate frame rigidly connected to the frame (6, 26) of the motor (121).

Description

Device for pumping a cryogenic fluid and filling station comprising such a device

The present invention relates to a device for pumping a cryogenic fluid and a filling station comprising such a device.

More particularly, the invention relates to a device for pumping a cryogenic fluid, the device comprising a fluid-tight housing intended to contain a pool of the cryogenic fluid, the housing containing a compression chamber in communication with the pool and a piston movable for compressing the fluid in the compression chamber, the piston being mounted at a first end of a rod, the device comprising a drive mechanism driving a second end of the rod to move back and forth in a longitudinal direction of travel, the drive mechanism comprising a motor equipped with a rotating shaft and a mechanical conversion system converting a rotational movement of the rotating shaft into a translational movement, the longitudinal direction of travel of the piston rod being vertical in an operating configuration of the device, the motor being rigidly fixed to an upper mounting structure.

Conventional solutions for actuating reciprocating piston pumps use a motor and a mechanical conversion system (connecting rod/crank and/or reduction gear and/or gearbox system) to convert the movement of the rotation shaft of the motor into a translational movement.

Most known cryopumps operate with the piston axis horizontal. This can be accomplished with a vacuum insulated cold end.

In a hydrogen station, the pump requires 24 hours a day to be available for pumping. Thus, the cold end is preferably placed in a vacuum insulated pool (dewar) of cryogenic liquid (sump) to ensure that it remains at cryogenic temperature. In this case, it is more appropriate that the piston is oriented vertically.

In this case, some adjustment is required in order to optimally support the pump and drive actuator (motor and associated mechanism). A universal joint system may be employed to transfer torque from the rotational output of the gearbox of the motor to the crank of the mechanical unit which converts the rotational movement supplied by the motor into a reciprocating translational movement of the piston rod. This allows for an optimal installation without requiring too small tolerances.

However, in this configuration, torque is transmitted through the shaft of the universal joint to a mechanism that converts rotational motion into translational motion. In practice, there is no satisfactory anti-torque system. The housing of the mechanism needs to withstand this torque. Thus, torque will be transferred through the entire pumping structure. This is unacceptable, in particular with respect to the mechanical strength of the tank containing the tank and the overall strength of the structure.

Even if these elements are sized accordingly, there is still a risk regarding potential vibration and fatigue problems.

With hydraulic solutions it is relatively easy to position the pump vertically, because the water hammer device is relatively small. The huge supply unit itself may be relocated to a few meters away. However, the overall layout and effectiveness is not well suited for the application.

A solution involving a linear actuator with a roller screw is also easy to implement due to its compactness. However, this solution is not well suited for high pressure low temperature applications due to its poor efficiency and reliability.

It is an object of the present invention to overcome all or some of the above-mentioned disadvantages of the prior art.

To this end, the device according to the invention, which in other respects corresponds to the general definition given in the preamble above, is essentially characterized in that the mechanical conversion system is also rigidly fixed to an upper mounting structure, which comprises or is rigidly connected to a separate mounting structure for the motor.

Further, embodiments of the invention may include one or more of the following features:

the upper mounting structure for the motor comprises a first support beam assembly(s), the upper mounting structure for the mechanical conversion system comprises a second support beam assembly(s) rigidly connected to the first support beam assembly(s),

the motor and the mechanical conversion system are rigidly fixed to two different beam portions, respectively, which are integral with or rigidly connected to a common beam extending in the longitudinal direction of the structure,

two beam sections are laterally connected to a common beam,

two beam sections located laterally on each side of a common beam,

at least one of the two beam sections is connected in cantilever fashion to a common beam,

at least one of the two beam sections is connected to the common beam via a disconnectable mechanical connection provided with a positioning system to allow adjustment of the lateral and/or longitudinal position of said section with respect to the common beam before the position is fixed,

the rotating shaft is coupled to the mechanical transformation system via a shaft comprising a connection system, such as a rigid connection or a universal joint,

the motor is suspended from its upper mounting structure,

the mechanical conversion system is suspended on its upper mounting structure,

the fluid-tight housing is suspended from the mechanical conversion system,

the device comprises several housings, each housing containing a compression chamber, a movable piston, the pistons being actuated by respective driving mechanisms, each driving mechanism being composed of a motor and a mechanical transformation system, said motor and mechanical transformation system being fixed to the same upper mounting structure or to separate mounting structures rigidly connected to each other,

the device comprises a tank of liquefied gas, in particular hydrogen, said tank being fluidly connected to the housing by a set of pipes configured to supply the fluid to be compressed to the compression chamber and to recover the fluid that has evaporated in the housing,

the mechanical transformation system that converts the rotational movement of the rotation shaft into a translational movement of the piston rod is a mechanical transformation system of the connecting rod/crank type,

the mechanical conversion system is accommodated in a housing, which is fixed to the upper mounting structure,

the motor is accommodated in a housing, which is fixed to the upper mounting structure,

the device is of the type having one compression stage, that is to say the fluid is compressed only once between the inlet system and the outlet system in the compression chamber,

the device is of the type having two compression stages, that is to say a device in which the fluid is compressed twice between an intake system and an exhaust system, the device comprising two compression chambers, the intake system being in communication with a first compression chamber and a second compression chamber, a transfer system for communication with the first compression chamber and the second compression chamber and configured to allow the fluid compressed in the first compression chamber to be transferred to the second compression chamber, a movable piston alternately compressing the fluid in the first compression chamber and the second compression chamber according to the direction of travel thereof, and the exhaust system being in communication with the second compression chamber,

the compression of the fluid in the compression chamber is caused by the pulling or compression of the rod.

The invention also relates to a station for filling tanks or pipes with pressurized gas, and comprising a source of liquefied gas, in particular a liquefied hydrogen tank; an extraction circuit having a first end connected to the source and at least one second end intended to be connected to a tank to be filled, the extraction circuit comprising pumping means according to any of the above or below features.

The invention may also be directed to any alternative apparatus or method including any combination of the above or below features within the scope of the claims.

Further specific features and advantages will become apparent from reading the following description with reference to the accompanying drawings in which:

figure 1 shows a schematic partial perspective view illustrating a first possible embodiment of a pumping device according to the invention,

figure 2 shows a schematic partial front view showing a first embodiment of the apparatus and comprising a cryogenic fluid tank,

figure 3 shows a schematic partial cross-section showing details of the device and in particular an example of the structure of the compression chamber,

fig. 4 shows a schematic partial perspective view from above, illustrating constructional details of the mounting structure of the device in another possible embodiment,

figure 5 shows a schematic partial front view illustrating a second embodiment of the device,

figure 6 shows a schematic partial front view illustrating a third embodiment of the device,

figure 7 shows a schematic partial top view illustrating a fourth embodiment of the device,

figure 8 shows a schematic partial side view illustrating a fifth embodiment of the device,

figure 9 shows a schematic partial view illustrating an example of a filling station using such a compression device,

fig. 10 is a schematic partial perspective view showing an example of the structure of a support for the mounting structure of the apparatus.

Fig. 11 shows a schematic partial perspective view of another example of a device.

The depicted apparatus 1 for pumping a cryogenic fluid comprises a fluid tight enclosure 13 intended to contain a pool of cryogenic fluid. The housing 13 may be vacuum insulated and house a compression chamber 3 in communication with the sump and a piston 5 movable to compress fluid in the compression chamber 3, see figure 3.

The piston 5 is mounted at a first end of the piston rod 50. The device 1 comprises a drive mechanism 21 for driving the second end of the rod 50 back and forth in the longitudinal travel direction a.

The driving mechanism 21 includes: a motor 121 (with a gearbox or similar device where appropriate) equipped with a rotation shaft 211; and a mechanical conversion system 212 that converts the rotational movement of the rotation shaft 211 into a translational movement of the lever 50. The mechanical conversion system 212 converting the rotational movement of the rotation shaft 211 into a translational movement of the piston rod 50 may be a connecting rod/crank type mechanical conversion system and is accommodated inside the housing.

For example, the rotating shaft 211 of the motor 121 is coupled to the mechanical conversion system 212 via a shaft that includes a connection system, such as a rigid connection or a universal joint.

A coupling involving a universal joint may allow for greater assembly tolerances.

The universal joint coupling between the two entities also allows for optimal transfer of "useful" torque in a relatively easy to maintain manner.

These elements (motor 121 and mechanical conversion system 212) may be housed in respective housings.

The housing of motion conversion system 212 can be easily removed to access the cold end located vertically below the mechanism (especially below the crankshaft in the case of a connecting rod/crank mechanism).

As shown, the longitudinal direction of travel a of the piston rod 50 is vertical when the device 1 is in the operating configuration. The motor 121 is rigidly fixed to the upper mounting structure 6, 26.

The mechanical conversion system 212 is also rigidly fixed to an upper mounting structure, which may be the same mounting structure 6, 26 for the motor 121 or a separate mounting structure rigidly connected to the mounting structure 6, 26 for the motor 121.

This means that the entire drive mechanism 21 can be rigidly mounted (in particular suspended) above the housing 13 via a structure capable of supporting the motor 121 and the conversion mechanism 212 without transmitting harmful torque into the structure.

In particular, the motor 121 (and its housing, where applicable) may be suspended from its mounting structure 6, 26. In particular, the motor 121 and its housing may be secured to the lower face of the upper mounting structure 26 via its upper portion (e.g., using screws or some other means).

Likewise, the mechanical conversion system 212 (and its housing, where applicable) may be suspended from its upper mounting structure 16, particularly by its upper portion being secured to the mounting structure (again, for example, using screws or some other means).

Preferably, each element 121, 212 is removable from the mounting structure 16, 26 to which it is secured, and is likewise removable independently of the other element 121, 212. This is advantageous for maintenance.

This structure can support the suspended container 13 for greater flexibility. This means that the upper end of the container 13 may be suspended from the lower end of the mechanical conversion system 212 (in particular its housing) by means of a connecting member 9, such as one or more shafts and/or a socket. Thus, the lower end of the container 13 may be located above ground level, rather than resting on a lower support.

In particular, as described in more detail below, the cryogenic conduit connecting this container 13 and the cryogenic liquid tank 17 may be a flexible conduit in order to absorb thermal shrinkage and tolerate minor misalignment.

In particular, the motor 121 and its housing may be rigidly connected to its upper mounting structure 26, 6. Likewise, the mechanical conversion system 212 and its housing may be rigidly connected to its upper mounting structure 16, 6.

The upper mounting structure for the motor 121 may include a first horizontal support beam assembly(s) 6, 26 that are connected to the load bearing structure 60, which may include vertical legs that rest on the ground.

Likewise, the upper mounting structure for the mechanical conversion system 212 may include the second support beam assembly(s) 6, 16.

As shown, the second beam assembly(s) are rigidly connected to the first support beam assembly(s) 6, 26. The two beam assemblies may be at least partially common. For example, the motor 121 and the mechanical conversion system 212 may be connected to two different portions 16, 26 of the same beam (e.g., a transverse beam) connected to the beam 6 (e.g., a beam extending in the longitudinal direction of the structure).

The two beam portions 26, 16 may be connected laterally to the common beam 6.

As shown, the two beam portions 26, 16 may be located laterally on each side of the common beam 6 (especially at the same longitudinal position along the longitudinal beam 6 of the structure).

As shown, at least one of the two beam portions 26, 16 may be connected to the common beam 6 in a cantilever manner. The two parts 16, 26 thus form together with the beam 6 a structure in the shape of a cross, in particular a latin cross.

These upper mounting structures 6, 16, 26 may be upper beams held at height via a set of legs or static structures. See, for example, the schematic depiction in fig. 10.

As shown, the load bearing structure 60 carrying the upper beams (mounting structures) 6, 16, 26 may comprise an upper structure supported by the legs and forming a support for each of the beam sections 16, 26 on which the motor and conversion mechanism are suspended (on both sides of the common beam 6), respectively. For example, the ends of the beam portions 16, 26 are connected to an upper element (e.g., a horizontal shaft or member) that is supported by the legs and forms the load bearing structure 60. In the example shown, both ends of the common beam 6 and the end of one of the two transverse beam portions rest against the structure 60 (the other end of the beam portion may protrude in a cantilever manner). Of course, a configuration is also conceivable in which the four ends of the mounting structure 6, 16, 26 (that is, the four ends of the "cross" formed by the upper mounting structure) are connected to the upper portion of the carrying structure 60 (for example, the four horizontal members forming the upper frame).

As schematically shown in the embodiment variant of fig. 4, at least one of the two beam sections, in particular the beam section 16 to which the mechanical conversion system 212 is attached, may be connected to the common beam 6 via a mechanical connection 8, which is breakable and preferably equipped with a positioning system to allow adjustment of the lateral and/or longitudinal position of said section 16 with respect to the common beam 6 before this position is fixed. For example, a self-centering semi-circular flexible fixation system may be envisaged. This flexible fixation system is of a type that allows a degree of movement to achieve an optimal fit, such as a semi-circular groove (self-centering) system. Other securing means are envisaged.

Thus, the motion conversion system 212 and in particular its housing may be on a small portion of the beam 16, which may be independently assembled on or removed from the main beam 6.

In the example of fig. 2, the device 1 comprises a liquefied gas tank 17, in particular a hydrogen tank. Tank 17 is fluidly connected to housing 13 by a set of conduits 10, 11, and these conduits are configured to supply the fluid to be compressed to compression chamber 3 and recover the fluid that has been vaporized in housing 13.

This tank 17 may rest on the ground. As previously mentioned, the conduits 10, 11 may comprise flexible portions.

In the above example, the device 1 comprises a single motor 121, a single mechanical conversion system 212 and a single container 13. Of course, as schematically illustrated in fig. 8, the device 1 may comprise several housings 13, each housing containing a compression chamber, a movable piston, actuated by a respective driving mechanism 21, each consisting of a motor 121 and a mechanical transformation system 212, said motor 21 and mechanical transformation system 212 being able to be fixed to the same upper mounting structure 6, 16, 26 or to separate mounting structures rigidly connected to each other.

A separation space 12 may be provided on the longitudinal beams 6 of the structure between two adjacent units in order to facilitate maintenance. During maintenance, an assembly consisting of the mechanical conversion system 212, its housing and the corresponding support beam 16 of one of the two units may be temporarily fixed at this portion.

The construction of the device provides a number of advantages.

In addition to transmitting the motion without unnecessary torque (no load cycle of the overall structure; less vibration is expected), the structure is also particularly well suited for easy maintenance (e.g. by removing the suspension element, in particular the housing, in order to access the mechanism (s)).

During maintenance of the cold end of the cryogenic pumping section, the drive mechanism (motor + possibly reduction gear or gearbox) need not be removed. The maintenance frequency of the motor part 121 is generally lower than that of the cold drive part in practice. The proposed structure allows access to the cold part (visual inspection, cleaning, replacement of seals, lubrication, etc.) without removing the motor part 121.

In the proposed configuration, the motor portion 121 is not required to support the weight of the transmission portion 212 and the cold portion due to the suspension structure described above.

The device 1 is compact and is positioned low to the ground. This is very suitable for integrating it into a filling station.

The motor 121 and associated reduction gear may be standard components, particularly with an explosion proof structure or enhanced safety.

The motor 121 and the conversion system 212 may be positioned in various opposite configurations, in particular horizontally, vertically, wherein the shaft 211 rotates on this axis or perpendicular to this axis, depending on the type of reduction gear system 212 known (helical gear, helical bevel gear, worm gear, helical parallel shaft, right angle reducer).

In the examples of [ fig. 1] and [ fig. 2], the motor 121 is vertical and perpendicular to an axis 211 that is connected to a mechanical motion conversion system 212.

In the configuration of fig. 5, the motor 121 and the output shaft 211 are horizontal and oriented transversely to the longitudinal beam 6 of the structure. This configuration makes it possible to save space under the upper mounting structure 6, 16, 26.

In the configuration of fig. 6, the shaft 211 connected to the mechanical conversion system 212 is located relatively low below with respect to the motor 121 (via a reduction gearbox or structure of gearboxes at the output of the motor 121). This configuration makes it possible to save space under the drive unit and to reduce the height of the connection 9 between the container 13 and the vertical support.

In the configuration of fig. 7, the motor 121 is arranged horizontally and parallel to the longitudinal beams 6 of the structure. This reduces the amount of volume below and laterally of the drive system.

The assembly comprises the motor 121 and its decelerator (if any) (from which the rotation shaft 211 protrudes as shown), and where applicable may be replaced by a torque motor (which therefore does not have a reduction gearbox or gearboxes). In this case, the oil is not problematic due to lubrication. Furthermore, in this case, the assembly is more compact and lighter in weight. Furthermore, such a motor assembly provides greater flexibility in terms of speed settings (speed profile, in particular rotational speed profile).

Fig. 3 schematically illustrates an example of a compression chamber (single compression stage) wherein an intake system 2 communicates with the compression chamber 3 and is configured to allow fluid to be compressed to enter the compression chamber 3, a piston 5 is movable to compress the fluid in the compression chamber 3, and a discharge system 7 communicates with the compression chamber 3 and is configured to allow compressed fluid to exit. The compression of the fluid in the compression chamber may be caused by the pulling or compression of the rod 50.

Of course, the invention is also applicable to pumps having two compression stages (e.g., two compression chambers and two compression stages, one for each of the two translational directions of movement of the piston).

Fig. 9 depicts an example of a station for filling a tank or a pipe with pressurized gas, and which station comprises a source of liquefied gas 17, in particular a source of liquefied hydrogen; a withdrawal circuit 18 having a first end connected to the source and at least one second end intended to be connected to a tank 190 to be filled. The extraction circuit 18 comprising the compression device 1 corresponds to a device according to any of the above-mentioned features.

Although the housing 13 is suspended from the mechanical conversion system 212, which itself is suspended from its upper mounting structure, as schematically shown in fig. 1, it is contemplated to provide one or more legs 20 that connect the housing 13 to the ground via flexible and/or adjustable connections 201. This may be done during maintenance operations and/or in the case of normal operations, for example, in order to better support the housing 13 and for example to absorb any vibrations that may be present.

Alternatively or in addition, the housing 13 may rest (e.g., via its lower end or bottom) on an upper surface of the support 202, such as a support with legs (see [ fig. 11 ]). This makes it possible to absorb part of the load transmitted to the container 13.

As illustrated in fig. 11, the one or more upper mounting structures to which the motor 21 and mechanical conversion system 212 are attached may be supported by a stationary structure 60, such as a beam that includes legs.

The stationary structure forms, for example, a frame and may be equipped with a base that is placed on the ground and on which the support 202 or the legs 20 for holding the container 13 may rest.

Such a structure 60 may be provided for each pumping assembly comprising a container 13, a motor and a mechanism 121 for driving a piston.

Claims

1. Device (1) for pumping a cryogenic fluid, the device comprising a fluid tight housing (13) intended to contain a pool of cryogenic fluid, the housing (13) accommodating a compression chamber (3) in communication with the pool and a piston (5) movable for compressing the fluid in the compression chamber (3), the piston (5) being mounted at a first end of a rod (50), the device (1) comprising a drive mechanism (21) driving a second end of the rod (50) to move back and forth in a longitudinal direction of travel (a), the drive mechanism (21) comprising a motor (121) provided with a rotation shaft (211) and a mechanical conversion system (212) converting a rotational movement of the rotation shaft (211) into a translational movement, in an operational configuration of the device (1) the longitudinal direction of travel (a) of the piston rod (50) being vertical, the motor (21) being rigidly fixed to an upper mounting structure (6, 26), characterized in that the mechanical conversion system (212) is also rigidly fixed to an upper mounting structure (6, 16) comprising a motor (121) for connecting the motor (121) to the mounting structure (6, 26) independently.

2. The apparatus of claim 1, wherein the upper mounting structure for the motor (121) comprises a first support beam assembly (6, 26), and the upper mounting structure for the mechanical conversion system (212) comprises a second support beam assembly (16) rigidly connected to the first support beam assembly (6, 26).

3. The device according to claim 2, characterized in that the motor (121) and the mechanical conversion system (212) are rigidly fixed to two different beam portions (26, 16), respectively, which are integral with or rigidly connected to a common beam (6) extending in the longitudinal direction of the structure.

4. A device according to claim 3, characterized in that the two beam parts (26, 16) are connected laterally to the common beam (6).

5. A device according to claim 4, characterized in that the two beam sections (26, 16) are located laterally on each side of the common beam (6).

6. A device according to any one of claims 3-5, characterized in that at least one of the two beam parts (26, 16) is connected to the common beam (6) in cantilever fashion.

7. A device according to any one of claims 3-6, characterized in that at least one of the two beam sections (26, 16) is connected to the common beam (6) via a disconnectable mechanical connection (8) provided with a positioning system to allow adjustment of the lateral and/or longitudinal position of said section with respect to the common beam (6) before the position is fixed.

8. The device according to any of the claims 3 to 6, characterized in that the rotation shaft (211) is coupled to the mechanical conversion system (212) via a shaft comprising a connection system, such as a rigid connection or a universal joint.

9. A device according to any one of the preceding claims, characterized in that the motor (121) is suspended from its upper mounting structure (6, 26).

10. The apparatus of any of the preceding claims, wherein the mechanical conversion system (212) is suspended from an upper mounting structure (16) thereof.

11. The device according to any of the foregoing claims, characterized in that the fluid-tight housing (13) is suspended from the mechanical conversion system (212).

12. The device according to any of the foregoing claims, characterized in that it comprises several housings (13), each housing containing a compression chamber, movable pistons, which are actuated by respective driving mechanisms (21), each consisting of a motor (21) and a mechanical transformation system (212), said motor (21) and mechanical transformation system (212) being fixed to the same upper mounting structure or to separate mounting structures that may potentially be rigidly connected to each other.

13. The device according to any one of claims 1 to 12, characterized in that the housing (13) rests via a support (202) and/or a set of legs (20) on a lower base, such as the ground.

14. The device according to any one of claims 1 to 13, characterized in that the upper mounting structure (6, 16, 26) to which the motor (21) and/or the mechanical conversion system (212) are fixed is supported by a stationary structure (60) comprising beams forming legs.

15. The device according to any one of the preceding claims, characterized in that it comprises a liquefied gas tank (17), in particular a hydrogen tank, said tank (17) being fluidly connected to the housing (13) by a set of pipes (10, 11) configured to supply the compression chamber with fluid to be compressed and to recover the fluid that has evaporated in the housing (13).

16. A station for filling tanks or pipes with pressurized gas, comprising a source of liquefied gas (17), in particular a tank of liquefied hydrogen; extraction circuit (18) having a first end connected to the source and at least one second end intended to be connected to a tank (190) to be filled, the extraction circuit (18) comprising a pumping device (1) according to any one of claims 1 to 15.